The present invention relates to a system for packaging articles, weighing the packaged articles, and applying a label indicative of information dependent on the weight of the weighed articles.
Facilities for packaging articles to be sold in supermarkets employ a system for automatically and continuously packaging articles on trays with films, weighing the articles, and applying to the weighed articles labels on which prices, etc., computed from the weights are printed. This system includes a packaging device for packaging the articles, and a weighing and labeling device for weighing and labeling the articles. The packaged articles are delivered from the packaging device to the weighing and labeling device. For reducing the space for installation of the overall system or for a greater efficiency, a unit for supplying the articles to the packaging device and a unit for picking up the articles delivered from the weighing and labeling device should be located closely to each other for enabling one worker to supply and pick up articles. In the conventional system for packaging, weighing and labeling articles, the packaging device and the weighing and labeling device are disposed parallel to each other, and a turn conveyor is positioned between the outlet of the packaging device and the inlet of the weighing and labeling device for turning the direction of feed of the articles through 180 degrees.
The turn conveyor is generally composed of a number of rollers disposed in a sectorial pattern. Since the inner periphery of the turning path is shorter than the outer periphery thereof, each of the rollers comprises a conical roller which is of a shorter diameter at its inner end so that the speed of feed of the articles, i.e., the peripheral speed of the roller, is lower at the inner periphery of the turning path. Therefore, the articles supplied to the conveyor are conveyed thereby while their orientation with respect to the direction of feed remains the same as that when they are introduced onto the conveyor.
The packaging device is supplied with the articles oriented transversely, i.e., with their trays having longitudinal axes directed perpendicularly to the direction of feed for allowing the films to wrap the articles and to be sealed smoothly. The packaged articles are then discharged transversely from the packaging device onto the turn conveyor. Unless the orientation of the articles is changed, the packaged articles as they are oriented transversely are turned 180 degrees and fed into the weighing and labeling device. In the labeling device, the articles are delivered longitudinally to guard against loss of orientation, i.e., with the longitudinal axes of the trays being oriented in the direction of feed so that the articles can always be fed to a labeling machine at a constant orientation and labeled at a prescribed position thereon. Accordingly, it is necessary to change the articles from the transverse orientation to the longitudinal orientation either when they are transferred from the turn conveyor to the weighing and labeling device, or on the turn conveyor.
It has been conventional practice to provide an abutment member for abutting against one side of the articles which are oriented transversely to hold that side temporarily against movement for thereby changing the orientation of the articles. With this arrangement, however, the abutment member may engage articles differently dependent on the size of the trays and may not turn the articles into the longitudinal orientation. When this happens, labels can not properly be applied to the articles by the labeling machine in the labeling device.
To eliminate the above problem, one solution has been to employ a conveyor device composed of a turn conveyor of a 90-degree arc and a vertical conveyor. In this conveyor device, the vertical conveyor is disposed in overlapping relation to the terminal end of the turn conveyor, the vertical conveyor having a direction of feed normal to the direction of feed of the turn conveyor at its terminal end. When the articles which are oriented transversely are turned 90 degrees by the turn conveyor, they are delivered to the vertical conveyor and discharged thereby in the longitudinal orientation. The conveyor device is advantageous in that the articles introduced transversely onto the turn conveyor are always turned into the longitudinal orientation by the vertical conveyor regardless of the size of the trays and can be picked up in a direction opposite to the direction in which they have been supplied to the turn conveyor. Therefore, labels can uniformly be applied to the articles in the weighing and labeling device. However, since the two conveyors are required, two drive devices are also necessary to drive the respective conveyors. The vertical conveyor also needs a lifting and lowering means for its operation. Accordingly, the structure of the conveyor device is complex and the cost of the overall system is high.
The turn conveyor must have its inlet properly connected to the outlet of the packaging device and its outlet properly connected to the inlet of the weighing and labeling device for smooth delivery of the articles. The distances between the inlets and outlets must be selected as optimum distances dependent on the dimensions of the packaging device and the weighing and labeling device. According to one system layout, the articles as discharged from the packaging device are turned to the right before they are fed into the weighing and labeling device, and according to another system layout, the articles as discharged from the packaging device are turned to the left before they are fed into the weighing and labeling device. Therefore, some systems use a turn conveyor for turning the articles to the right and some systems employ a turn conveyor for turning the articles to the left. As a result, different types of turn conveyors have to be provided for use in packaging, weighing and labeling systems, which are therefore rendered high in cost.
In the weighing device for weighing the articles discharged from the turn conveyor and labeling the weighed articles, the articles have to be fed transversely in constant positional relationship into the labeling machine in order to apply labels properly to the articles irrespectively of the size of the articles. A device therefore would be needed to displace the articles laterally to a prescribed position and feed them to the labeling machine at a constant orientation.
There is known an automatic labeling device for attracting a label issued from a printer against the lower surface of a suction head under the suction produced by a blower and for changing the direction of air flow from the blower to apply the label to an article when the article is positioned below the suction head. Another known automatic labeler includes a suction box for attracting a label, which is attached to the lower end of a labeler rod for movement between an upper label receiving position and a lower label applying position, the suction box being connected to a blower by a bellows hose, as disclosed in Japanese Utility Model Publication No. 57-36571 filed by the present applicant. The former automatic labeling machine is however disadvantageous in that it is difficult to apply labels to articles properly at a prescribed position, resulting in irregularly positioned labels applied to the articles. With the latter automatic labeler, since the suction box is moved to the lower label applying position, labels can be applied to articles at a constant position. However, because the labels are subject to suction through the suction box and the bellows hose even when the labels are applied to the articles, some labels may tend to remain attached to the lower surface of the suction box under the suction, without being applied to the articles, due to the nature of the adhesive coated on the reverse side of the labels or the condition of the surface of the articles where the labels are to be applied.